/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.hzandyy.zookeeper.demo;

import lombok.Getter;
import lombok.Setter;

import java.util.ArrayList;
import java.util.List;

/**
 * Auxiliary cache to handle changes to the lists of tasks and of workers.
 */

@Getter
@Setter
public class ChildrenCache {

    protected List<String> children;

    public ChildrenCache() {
        this.children = null;
    }

    public ChildrenCache(List<String> children) {
        this.children = children;
    }

    List<String> getList() {
        return children;
    }

    List<String> addedAndSet(List<String> newChildren) {
        ArrayList<String> diff = null;

        if (children == null) {
            diff = new ArrayList<String>(newChildren);
        } else {
            for (String s : newChildren) {
                if (!children.contains(s)) {
                    if (diff == null) {
                        diff = new ArrayList<String>();
                    }

                    diff.add(s);
                }
            }
        }
        this.children = newChildren;

        return diff;
    }

    List<String> removedAndSet(List<String> newChildren) {
        List<String> diff = null;

        if (children != null) {
            for (String s : children) {
                if (!newChildren.contains(s)) {
                    if (diff == null) {
                        diff = new ArrayList<String>();
                    }

                    diff.add(s);
                }
            }
        }
        this.children = newChildren;

        return diff;
    }
}
